ASTM E1996 was first published in 1999 to address impact from missiles such as wind-borne debris. Joseph Reed, PE, Senior Director at Intertek, reviewed the evolution of the standard and ongoing efforts to update it to merge with current building codes and preventive actions for high wind events.

Reasons for updating include rigid interpretations of existing criteria that have led to unwieldly test programs, plus the need to harmonize with market practices and those of local jurisdictions. The most recent edition, ASTM E1996-17, revised requirements for substitutions to assemblies that have initially qualified by having three initial specimens identical in all ways except for anchorage and mounting to pass all performance requirements.

Each method of anchoring must be qualified by testing a specimen under maximum load conditions on the anchoring method or by engineering analysis. The exterior “sacrificial” lite must undergo additional test if the thickness is decreased, but not if it is increased. Reed noted that ASTM E1996-17 is not a code standard and will not be until 2021 at the earliest.

Testing requirements as specified in ASTM E1996-14a remain unchanged, although technical interpretations are needed. Impact test criteria for tears is defined as gaps 1/16-inch width as well as five inches high “through which air can pass,” but there remains ambiguity as to exactly what a “tear” is and interpretation problems in pass/fail criteria as stated.

Clarifications are in order, and ASTM work group WK57600 has been formed to deal with them. Among the proposed changes is to add a penetration requirement, remove the tear width requirement and include a force of application to be applied to the three-inch test sphere. There are numerous disagreements as to how the impact testing pass/fail criteria should ultimately be defined.

Opportunities to participate include joining the ASTM E06.51.17 task group on impact resistance through an existing ASTM membership, and/or joining the WK57600 work group by contacting Reed directly. The next task group meeting was set for April 10 in San Diego, according to Reed.